The present invention relates to a coating apparatus for providing a uniform superficial protective layer on the surface of a small-sized card such as a license or an ID card.
In recent years, cards-have progressed remarkably and utilization thereof has expanded sharply. In particular, various types of cards relating to identification such as an ID card or a license are also increasing steadily.
These cards naturally need to be protected from forgery and from scratches caused by handling. For these cards, a specific photographic paper is frequently used, and a laminating method has been popular for them. In the course of laminating, however, bubbles tend to enter, and time-consuming punching is required after laminating, which cause cost increase. In contrast to this, among those methods for coating resins directly, there are some methods which are excellent in terms of cost. For example, Japanese Patent Application Nos. 90261/1989 and 90266/1989 disclose a method wherein a coating roll is used.
However, the aforementioned method is a bead coating therefore, beads of a coating solution are hung from the trailing edge of a card, causing the so-called thicker layer on the trailing edge which makes a protective layer to be uneven. In addition to the foregoing, many portions on an apparatus are exposed to coating solutions, which makes handling difficult.
Due to the nature of a card, there is a demand for a card having a superficial protective layer excellent in resistance to scratches, waterproofing, resistance to chemicals and in surface smoothness.